The invention relates to an apparatus for the production of glasses by the press-and-blow process having a plunger which can be forced inside a press mould into a glass melt to form a parison therefrom.
Prior art apparatuses of the kind specified are suitable for the large scale serial production of industrial glasses and therefore enable automatic feeders to be used from which before each pressing operation the press moulds are supplied with a droplet of molten glass of sufficiently constant weight. However, in the manufacture of individual glasses the numbers produced are frequently so small that it is not worthwhile adjusting an automatic feeder to the required droplet weight, since this as a rule is a time-wasting process of trial and error. On the other hand, if the press moulds are manually fed with droplets of molten glass, the droplet weight fluctuates to such an extent that the parisons which can be produced by the prior art apparatuses of the kind specified are very inaccurate and spoil the subsequent blowing which is supposed to be simplified by pressing.
It is, therefore, an object of the invention to provide an apparatus for the production of glasses by the press-and-blow process which, in spite of any inaccurate droplet weight, enables parisons which retain their desired shape and mass to be pressed and quickly further processed by blowing.